This is a big deal for ebooks. I used to be in charge of sales for a major science fiction and fantasy publishing program and when looking at sales data of our top markets it was no coincidence that they were all cities with a major naval presence, Norfolk Virginia and Groton Connecticut beating many larger metro areas in sales for example.
When you are at sea for long stretches of time books are a major source of entertainment and escapism. Space is also a premium. The military is a major ebook and ereader market segment worth paying attention to. ~ eP